Learning from the Past: Using the Stars as Gateways
This week lecture was very interesting. I could perfectly see the the correlation between the theme of the course and the topic of the lecture. The lecture was all about how scientists could tell things about past galaxies by using aspects of the new galaxy. Some things that were mentioned was the theory of distance and reach and also the black hole theory and quenching. All of these help to distinguish parts of the past environment.
The theory of distance is very interesting yet simple. It basically states that the further away an object is, the longer it will take for its light to reach. In the lecture, we referenced difference objects such as the moon sun and stars. The moon takes only one second for its light to hit earth because it’s relatively close. However, the sunlight takes at least 8 minutes to reach earth because it’s so hot that it is not as close to the earth as the moon. Yet, it takes about 4 years for the light of the star to reach earth because it’s farther out than the moon and the sun.
The black hole theory is the theory that discusses star formation quenching. It is the idea that when two galaxies connect, they feed the black hole. This causes gas to heat up as well as being pushed back.This theory connects closely to quenching and explains the formation of different galaxies thus connecting it to the past by using modern speculation to determine why certain galaxies were formed the way that they were.
The lecturer also talked about Halo quenching. This is a particular way that the galaxy has been suppressed. It is done in a circular motion. Quenching is a way to look into the past to learn new things about different and older galaxies that we would otherwise not know much about. This connects more to the theme of the course as a way to look into and learn from the past that is present and modern day things such as looking at the aftermath of the quenching effects.
The galaxies and all the other mysteries of outer space are cool learning topics. What’s even cooler is to see how how they connect to the past. It’s easy to use modern galaxies to make predictions on what the past may have looked like. These predictions can be made by looking at things such as theories like the black hole theory and the distance theories or by looking at quenching which is connected to formation. All of these aspects give a look into the past by telling what these galaxies could of look like or been made of years ago. Hence, this lecture connected nicely with the theme of the course because it shows that when we look into present galaxies we could use them to see the past as well. The past is not that far from the future in most cases. This lecture was a perfect way to end the course.